In the related art, for example, as disclosed in Patent Literature 1, a tracking control apparatus that controls the traveling of a host vehicle so as to track a preceding vehicle is known. Such an apparatus controls the traveling of the host vehicle by detecting the preceding vehicle traveling in a host lane. Here, the preceding vehicle is detected using an object detection sensor that, for example, transmits a detection wave toward the front direction of the host vehicle and simultaneously receives a detection wave reflected from the object. The object detection sensor detects a distance to the object from the host vehicle, a relative speed of the object with respect to the host vehicle and an angle (a lateral position) between the object and the host vehicle with accuracy according to each resolution of the distance, the speed, and the angle.